聚合抗褐飞虱基因bph20（t）和bph21（t）及抗稻瘟病基因Pi9水稻株系筛选

【目的】筛选聚合抗褐飞虱和抗稻瘟病基因水稻材料,为培育新型抗褐飞虱兼抗稻瘟病的水稻新种质提供参考。【方法】利用常规育种、分子标记辅助育种和抗病虫鉴定相结合的手段,将抗稻褐飞虱基因bph20（t）和bph21（t）以及广谱高抗稻瘟病基因Pi9聚合到优良保持系博ⅢB的遗传背景中。【结果】bph20（t）的分子标记RM540和BYL7、bph21（t）的分子标记RM5348和RM222未在稻褐飞虱抗、感亲本间扩增出特异条带,无明显的多态性,不能用于该育种群体抗褐飞虱基因bph20（t）和bph21（t）的检测。Pi9的显性分子标记pB8以及共显性分子标记PB9-1在稻瘟病抗、感亲本之间可扩增获得特异条带,具有多态性,可用于Pi9基因的检测。经抗虫鉴定并利用标记PB9-1对BC6F2群体的22株材料进行PCR扩增,含有Pi9基因杂合体的有10株,纯合体有6株,不含Pi9基因的有7株。用源自广西南宁田间感褐飞虱和稻瘟病菌株进行多次抗病虫鉴定,筛选获得一批抗褐飞虱材料,其中抗性与抗虫亲本BPH54相当的材料有6份,在这6份材料中含有Pi9基因且抗稻瘟病的材料有5份,对稻褐飞虱的抗性与供体亲本BPH54水平相当。【结论】通过常规育种、分子检测和抗虫鉴定相结合的办法,筛选获得5份聚合褐飞虱抗性基因（bph20和bph21）和抗稻瘟病基因Pi9的抗或高抗水稻中间材料,为选育新的双抗保持系和不育系提供种质材料。

Pyramiding brown planthopper genes, bph20（t）and bph21（t）, and rice blast resistant gene Pi9 in rice （Oryza sativa L.）

Objective The present study was conducted to screen rice materials pyramiding brown planthopper and rice blast genes for providing reference on breeding new rice germplasms with resistance against brown planthopper （BPH） （Ni-laparvata lugens Sta°l） and rice blast caused by the fungus Magnaporthe grisea. Method By using conventional breeding, molecular marker-assisted breeding and BPH resistance bioassay, BPH resistance genes viz., bph20（t） and bph21（t）, and the broad-spectrum and highly resistant blast resistance gene Pi9 were pyramided into the genetic background of an elite main-tainer line BoIIIB. ResultThe molecular markers RM540 and BYL7 for bph20（t）, as well as RM5348 and RM222 for bph21（t）, could not amplify specific bands and showed no obvious polymorphism among the resistant parents and susceptible parents, so they could not be used in molecular marker-assisted selection of the present breeding population. The dominant molecular marker pB8 and codominant molecular marker PB9-1 for Pi9 could amplify specific bands and showed polymorphism among the resistant parents and susceptible parents, and could be used in the molecular marker assisted selection of the present breeding population. The marker PB9-1 was used for PCR amplification of 22 rice plants in BC 6 F2 population after insect resistant identification, It was found that 10 plants was heterozygote with Pi9 gene, 6 plants was homozygote and 7 plants had no Pi9 gene. By insect resistant identification using rice plants susceptible to brown planthopper and rice blast in field of Nanning, a series of rice plants against to brown planthopper, and 5 accessions had Pi9 gene and resistance to rice blast among 6 accessions with equivalent resistance of parent BPH54. Conclusion By using conventional breeding, molecular detection and insect-disease resistance bioassay, 5 accessions of above resistant rice intermediate materials pyramiding brown planthopper genes and rice blast gene, which could provide germplasm meterials for breeding new double resistant maintainer line and sterile line.